The present invention relates to a door controller and a method for inputting or adjusting one or more reference positions used by the door controller and, in particular, to a method for quickly teaching the controller accurate reference positions along a door travel path.
Modern elevator door controllers use travel curves to dictate the movement of a door along a track between its closed and open positions. Such travel curves define the desired door speed as a function of the door position or of the time. A pulse encoder is frequently used to provide the controller with a signal indicating the door position. Such a system is described in European published application EP-A1-0665182. In an initial learning run, the controller implements a door opening operation during which the door is moved by a drive along a track from the closed position to a fully open position where further movement of the door in the opening direction is prevented by a mechanical stopper or alternatively by an open-limit switch mounted on the track. Whereas the stopper physically restricts motion of the door along the track, the open-limit switch, when activated, signals the controller to stop the drive and thereby also restricts motion of the door along the track. During this learning run the total distance from the closed position to the fully open position is registered by the pulse encoder into a memory accessible by the controller. Accordingly, the total travel path for the door is known to the controller. Intermediate switches may be mounted along the track to signal-changes in the desired travel curve to the controller (for example there may be an intermediate switch to indicate the position where the motion of the door should change from a constant creeping speed to full acceleration). Alternatively, the controller can automatically calculate these intermediate reference positions using the total travel distance and register these into the memory as discussed in Japanese patent document JP-A-2000016730.
After initial installation, it is important to make adjustments to the reference positions so as to compensate for mechanical tolerances and most importantly to ensure that the edge of the fully open door is flush with the door jamb. Adjustment may also be required during modernization or maintenance of the elevator installation.
Conventionally, any adjustment of the reference positions is performed by manually accessing the door track and shifting the respective switches or stoppers along the track until they are in the correct positions and then instructing the controller to repeat the learning run. This is a laborious and time-consuming task, particularly in an elevator installation where it may have to be repeated for each individual landing of the installation. Furthermore, the task can be very frustrating if only minor adjustment is required.